This updates the USB Gadget stack to Linux-3.15.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Conflicts:
	drivers/usb/core/Makefile

This renames USB to USB_HOST since this is what the symbol really
means. Introduce a USB symbol which is selected by both USB_GADGET
and USB_HOST. This gives us a symbol to let common USB code depend
on.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add helpers to get the dr_mode and the phy_mode.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

move to linux usb driver organisation

as following

drivers/usb/core
drivers/usb/gadget
drivers/usb/host
drivers/usb/otg

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>